Floating stone



G. c. FAVRE FLOATING STONE Filed Nov. 16, 1923 INVENTOR szmmrwkz,

I BY W 7V AIiORNEY Patented Oct. 6, 1925.

' GEORGE e; FAVRE, asoummms, messen r assrenon m AMERICAN or;

a rman COMPANY; or sonrnnmn'enj 'lvmssncnusmrs, EA voLUNrA-mt Assoom*rmonrme sronnl Taallrwhlomitmay concern: v I Be i ikDQWH t at LG'EQRGE-.F 1 -E a! citizen o he- S is C nfederation, resid ng; at Southbridge,jin therlcountyof Worcester and State of Massachusetts, have inventedcertain new and useful Improvements in Floating Stones of which thefollowing is a specification.

The present invention relates to an improved form of floating stone foruse in connection with bevelled edging machines used in grinding bothfaces of an ophthalmic lens simultaneously.

An important object of the invention is to provide a floating stone ofthis nature and driving means therefor that will allow the stone toreadily adjust itself to the various shaped lenses used and tofacilitate driving of the stone at all times, without in any wayinterfering with the movement of the stone when in use.

Another object of the invention is to provide a device of this naturethat will be strong, durable, comparatively simple and inexpensive inconstruction and that is exceptionally well adapted for the purposes forwhich it is designed.

Other objects and advantages of the invention will become apparentduring the course of the following description.

In the drawings wherein like numerals are employed to designate likeparts throughout the same,

Figure 1 is a front elevation of the invention partially in section forthe purposes of illustration, 7

Figure 2 is a fragmentary enlarged detail of the driving connection, and

Figure 3 is a fragmentary sectional detail of the stone mounting.

In the drawings, wherein for the purposes of illustration is shown thepreferred embodiment of the invention, the numeral 5 designates thedriving shaft which is supported at one end as at 6 and at the oppositeend as at 7 A suitable driving connection such as the pulley wheel 8 iskeyed to one end of the shaft 5 and is adapted to rotate the same.

The shaft 5 is provided with the curved reduced portion 9 the thinnestpoint of which is at 10, as is clearly shown in Figure 1 of thedrawings. The stone 11 is carried by the member 12 which may be in theform of I aplate-having the centrally disposed aperture 13 which isslightly larger than thefin ished portion;10; of the? shaft .5. --Theplate 52 isc amfered asat'lk around theapertn-re 13, thus allowing thestone andmounting 12 to be rocked on the shaft 5.

A spanner 15 is keyed to the shaft 5 and has laterally extending fingers16 which are adapted to engage with the balls 17 carried by thelaterally extending fingers 18 which are formed integral with the plate12. It will, of course, be understoodthat the balls 17 will be securedin a suitable pocket in the finger 18 so as to prevent accidentaldisplacement thereof and at the same time will be so disposed that theportions 18 may be moved along the same with comparative ease. I

It will thus be seen that upon rotation of the pulley wheel 8 due to thefact that the spanner 15 is keyed to the shaft 5 the same will berotated and the fingers 16 will en-.

gage the fingers 18 carried by the stone portion 12 and therefore thestone 11 will be rotated. When a curved lens is placed within the groove19 of the stone, the stone will be slightly tilted or rocked, thuscausing the finger 18 at one end to move along the pulley 17 in onedirection and the finger at the opposite end in the other direction. Ofcourse, the reduced port-ion 9 and the chamfered edges 14 will permit ofthe tilting of the stone 11 to whatever degree is necessitated by thecurvature of the lens.

Of course many forms of spanners may be designed as well as the fingers18. It is therefore to be understood that the form of my inventionherewith shown and described is to be taken as the preferred embodimentof the same and that various changes in the shape, size and arrangementof parts may be resorted to without departing from the spirit of myinvention or the scope of the subjoined claims.

Of course, it will be seen and understood that this stone mounting is soarranged that it will adapt itself to any form of lens to be ground. Inother words, a flat, toric or meniscus lens may be ground in the groove19 of the stone and the lens contacting in the groove 19 will cause thesaid stone to receive the lateral displacements caused by the said lens.The lens will be held incontaot with the said stone as is ordinarilydone, that is,

by means of clamping means carried by a rotatable shaft whichaccommodates a suitable former to rock the said lens clamping shaft toand from the stone, and resilient means to hold the lens in perfectcontact with the stone at all times during the grinding operation, thestone being so mounted and adaptable to all forms of ophthalmic lenseswill be of a universal nature and provide what may be properly termed afioat in r grindstone.

aving thus described my invention, what I claim is:

1. A device of the character described comprising a shaft, a stoneloosely mounted thereon, having fingers extending therefrom, a spannerkeyed to the shaft and having fingers for cooperation with the fingerscarried by said stone and ball members interposed between the saidcooperating fingers.

2. A device of the character described comprising a shaft having acurved reduced portion, a stone having a centrally disposed aperture andchamfered portions arranged around the aperture to allow the said stoneto rock on the shaft, fingers extending from the stone, a spanner keyedto the shaft and having fingers adapted for cooperation with the fingerscarried by the stone.

GEORGE C. FAVE-E.

